This invention relates to wheel adjustment/alignment methods for vehicles, and, more particularly, relates to apparatus and methods for adjusting the control arm/wheel spindle relationship at an upper or lower ball joint connection to produce changes in the camber, caster or camber/caster combination angle of a vehicle wheel.
Most vehicles consist of a tire/wheel mounted to a spindle which is attached to the vehicle through upper and lower control arms with the main connection being through ball joints mounted to the control arms. Some vehicles, however, are manufactured without provision for adjusting camber angle in the wheels. For example, some vehicles utilize an xe2x80x98Axe2x80x99 shaped upper control arm with xe2x80x98silent-blocxe2x80x99 type pivot isolators pressed into the inner pivot locations of the arm. The inner control arm in some such cases has a xe2x80x98uxe2x80x99 shaped bracket welded into it, with cross-holes in the inner bracket and inner control arm for locating the mounting bolts that engage and clamp the xe2x80x98silent-blocxe2x80x99 pivot isolators. This arrangement locates the inner pivots of the upper control arm in a fixed position with no means of adjustment.
The camber and caster angles of the tire/wheel (relative to the vehicle frame) directly effect vehicle handling and tire wear and is therefore of great importance. Camber angle is typically specified by the factory at a specific vehicle ride height (the distance from the ground to some point in the vehicle suspension corresponding to the vehicle frame center of gravity). The camber angle established between the plane of the tire and wheel and the vertical plane through the vehicle frame is directly impacted by any changes in the suspension components. Such changes can occur through damage to the components or through modification, intentional or unintentional, to the vehicle ride height. Thus, vehicles with raised or lowered ride height or damaged suspension links will typically not maintain proper camber angle and require means for readjusting the camber angle to the original specifications if handling and tire longevity are not to be sacrificed. Moreover, it may become desirable to correct a mis-aligned vehicle with other than strictly camber corrections.
One current means for adjusting camber angle consists of changing the relative position of the control arm to the vehicle at the body mounting points. This allows the control arm, and thus the ball joint position, to be moved laterally with respect to the vehicle, thereby changing the camber angle of the spindle and the tire/wheel. This method will not work if the vehicle""s control arm mounting scheme prevents replacing the fixed control arm body mounts with an adjustable mounting apparatus.
Another current means for adjusting camber angle provides for replacement of the upper or lower ball joint with an offset ball joint that, when rotated, allows changes of the position of the spindle mounting point around an offset arc. While this enables the camber angle to be modified, it at the same time modifies the caster angle, sometimes undesirably, due to its fixed radial offset arc. Further improvements could thus be utilized
This invention provides methods for selective positioning of a vehicle ball joint relative to a control arm to provide adjustability of wheel camber, wheel caster, and/or a combination of wheel camber and caster. The method provides for simplicity in installation and adjustment, requires no modification of other suspension components, and provides for adjustment of wheel camber independent of caster adjustment.
The method of this invention for adjusting the relative position of a vehicle ball joint and a central axis of the control arm opening includes the steps of affixing a stud to the ball joint and positioning the stud through the control arm opening. The stud is affixed to the ball joint at an offset relative to a central axis of the ball joint. Linear movement of the stud perpendicular to the axis of the control arm opening is guided while rotational movement of the stud in the opening is stabilized, the offset being secured against possibility of significant rotation once the stud is positioned at the control arm opening. When desired adjustment is achieved, the stud is secured at the selected position relative to the axis of the control arm opening.
The stud extends from a slide, the slide being affixed at an end of the ball joint and defining the offset. An insert is extended through the control arm opening, part of the insert being received adjacent to a guide. Substantially coextensive slots at the guide and the insert are provided for receiving the stud. The slide is received and rotationally stabilized at the guide. Movement of the stud and the slide linearly at the slots and the guide, respectively, position the ball joint.
The method may accommodate caster correction, camber correction, or a combination thereof. Selectable camber correction of a vehicle wheel is accomplished by extending the insert through an opening at a spindle of a vehicle""s control arm with the slot selectively oriented (in a caster neutral position).
It is therefore an object of this invention to provide methods for selective positioning of a vehicle ball joint relative to a control arm to provide adjustability of wheel camber, wheel caster, and/or a combination of wheel camber and caster.
It is another object of this invention to provide a method for selective vehicle wheel angle positioning that provides for simplicity in installation and adjustment on a vehicle, requires no modification of other suspension components, and provides for adjustment of wheel camber independent of caster adjustment.
It is yet another object of this invention to provide a method for adjusting relative position of a vehicle ball joint and a central axis of a control arm opening including the steps of affixing a stud to the ball joint, positioning the stud through the control arm opening, guiding linear movement of the stud perpendicular to the axis of the control arm opening while rotationally stabilizing the stud in the opening, and securing the stud at a selected position relative to the axis of the control arm opening.
It is still another object of this invention to provide a method for adjusting relative position of a vehicle ball joint and a central axis of a control arm opening including the steps of affixing a stud to the ball joint at an offset relative to a central axis of the ball joint, positioning the stud through the control arm opening, providing for securement of the offset against possibility of significant rotation and for guidance of linear movement of the stud perpendicular to the axis of the control arm opening, and securing the stud at a selected position relative to the axis of the control arm opening.
It is still another object of this invention to provide a method for selective positioning of a vehicle ball joint securable between a control arm and a wheel mounting, the method including the steps of affixing a stud extending from a slide at an end of the ball joint, extending an insert through the control arm, receiving a part of the insert adjacent to a guide, providing substantially coextensive slots at the guide and the insert, receiving and rotationally stabilizing the slide at the guide, with the stud through the slots, and moving the stud and the slide linearly at the slots and the guide, respectively, to position the ball joint.
It is yet another object of this invention to provide a method for selectable camber correction of a vehicle wheel that includes extending an insert having a slot through an opening at a spindle of a vehicle""s control arm with the slot selectively oriented, receiving a guide adjacent to the insert so that a slot at the guide is substantially coextensive with the slot of the insert, affixing a ball joint at one end to the spindle and at another end to a slide having a stud extending from one side thereof, and positioning the slide for linear movement at the guide with the stud through the slots of the guide and the insert to thereby position the stud along the slots.
With these and other objects in view, which will become apparent to one skilled in the art as the description proceeds, this invention resides in the novel construction, combination, arrangement of parts and method substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that changes in the precise embodiment of the herein disclosed invention are meant to be included as come within the scope of the claims.